The present invention relates to physical object location and more particularly but not exclusively to physical object detection for keeping track of the objects, which may be playing pieces or tokens in a game, and moving the objects. The object detection may be pat of a game or simulation platform.
Traditionally, games have been played on a specially marked out playing surface or game board, and tokens are moved around the board in accordance with a set of rules.
More recently, however, games, simulations and the like have been run on computers, and many of the traditional board games have been computerized. Typically, the computerized board game has involved an animated board appearing on the screen, with animated playing tokens being moved around the board. Interactions between the player and the computer are carried out in the normal way using standard interface devices such as a keyboard, mouse and joystick.
Gameplay involving multiple players is awkward, especially if play is restricted to a single computer. Also it can be difficult for people used to tokens on a board to adjust to screen displays.
There have thus been numerous attempts to enable a computer to use physical playing pieces and a game board so as to make the computer/human interface as natural as possible.
The earliest attempts, from the times when computers able to play games first because available, involved the player setting up a board with playing pieces, making his move on the board, keying his move in to the computer and then waiting for the computer to indicate its move. The computer""s move was then physically made by the user on the board. However there was no direct interaction between the computer and the board.
A number of existing patents allow for direct interaction between the computer and physical playing pieces set on a board. The interaction is typically based on apparatus bad within the playing pieces or tokens and corresponding sensing apparatus connected to a computer. In order for the computer to interact directly with the pieces, the human players and the board, such a sensing mechanism is needed to enable automatic location of the physical pieces or tokens relative to the board and preferably also to provide an ability to distinguish between the tokens.
A number of patents to Wacom describe electronic drawing devices or styluses. The movement of the stylus over a tablet is traced electronically and used to generate computerized drawing. Excitation is applied to a resonant circuit in the stylus, electromagnetic radiation emitted by the resonant circuit is detected by a sensing mechanism and location processing is used to locate the stylus. U.S. Pat. No. 6,005,555 is one such patent, in which a position detecting apparatus is disclosed which is capable of detecting position pointing devices of any combination simultaneously out of plural position pointing devices. A frequency of a resonance circuit provided inside a position pointing device is set by a command signal transmitted from a tablet, causing plural position pointing devices placed on the tablet to have different frequencies, thereby suppressing electromagnetic interference among position pointing devices on the tablet, so that simultaneous detection becomes available.
A key problem with the use of such a system in conjunction with a gameboard is that a layer of conductors arranged in a grid is placed on the tablet to give the device sufficient resolution in locating the stylus. In a game, the gameboard, however, should preferably be seen without interference.
U.S. Pat. No. 5,188,368 to Ryan describes playing pieces having tuned circuits within. Each or the tuned circuits is tuned to a different frequency so that the playing pieces can be distinguished. The game board is divided into cells and coil circuits are embedded within the playing surface or game board, one per cell. The coil circuits are activated in turn, to excite the tuned circuits of any piece that may be located in the cell. A response is taken to indicate that a piece is located in the cell.
U.S. Pat. No. 5,853,327 to Gilboa, describes playing pieces containing an electromagnetic transponder arranged to give a coded signal identifying the individual playing piece. The game board is a flat surface on which are placed paper sheets representing the game. The board is divided into cells, each of which comprises an electromagnetic excitation coil built into the board. The cells are excited on a row and column basis and the position of each piece is determined.
In both of these solutions, the coil or transponder has to be built into the playing surface. Neither of these solutions disclose a combination of a sensing apparatus with an electronic screen.
Applicant""s co-pending application. U.S. Ser. No. 09/1382,167 describes an active solution, meaning a solution involving playing tokens having powered circuitry therein, in which individual tokens visually detect activated pixels on a flat display screen used as a game board. The token transmits a signal when a pixel, over which the token is positioned, is activated, and the system is able to use the transmitted signal to deduce the position of the token because it knows which pixel was activated at the given time. Embodiments allow for search patterns of the activated pixels, and tokens with individually identifiable signals. The signals may be infrared, ultrasound and the like. In addition, embodiments provide for artificial computer players, or for remote players located over a network and whose moves may be made by a robot arm.
This solution allows detection to be provided in conjunction with an electronic screen. Being an active solution, however, it requires the tokens to have an independent power source. That is to say, there is a battery which requires to be replaced from time to time. Furthermore dirt picked up on the bottom of the piece can obscure the sensor.
Embodiments of the present invention allow for accurate determination of the location and identity of playing pieces on a playing board, such that one or more players are able to play a game in which some of those players may be artificial players and some may be remotely located players, playing for example over a network.
Embodiments of the present invention also provide for a solution which may be used in conjunction With an electronic screen and wherein a small amount of dirt on the playing piece will not interfere with use.
The present invention preferably utilizes a robotic arm, in conjunction with an accurate location and identification system, in order to move tokens in the game on behalf of artificial or remote players.
According to a first aspect of the present invention there is thus provided a method of detecting each one of a set of physical objects, placed in association with a graphic display device, each of said objects comprising an identifier, the method comprising:
placing at least one of said objects at a location in association with said graphic display device,
detecting said identifier by means of a detector,
outputting a signal from said detector, which signal bears information of said location and
determining from said signal, information of said location.
In a preferred embodiment, each object has a unique identity within said set, wherein said indicator is indicative of said identity, said signal output from said detector further bearing information of said unique identity and wherein said step of determining comprises determining said unique identity.
In a further preferred embodiment, said identifier is a visual identifier, and said step of determining includes image processing.
In a farther preferred embodiment, said identifier is an electronic identifier, said identifier producing an output which is identifiable within said set.
In a further preferred embodiment, said electronic identifier is a resonant circuit and said output is electromagnetic radiation at a frequency unique within said set.
In a further preferred embodiment, said identifier is a transmitter, there is provided a step of triggering said transmitter to emit a signal, there is provided a step of measuring one of a group comprising the time delay between triggering and a receipt of said emitted signal a phase change to each one of a plurality of receivers and, and there is provided a step of deducing the location of the object by comparing said one of said group to each of said plurality of receivers.
Preferably, said transmitter is any one of a group comprising an ultrasound transmitter, an infrared transmitter, a radio frequency transmitter and a microwave transmitter.
Preferably, said physical object is externally powered.
Alternatively, said physical object is internally powered.
Preferably, said physical object is any one of a group comprising a game piece, a simulation piece and a pointer.
In an embodiment, said graphic display device is a flat screen graphic display device.
Alternatively, said graphic display device device is a tablet device.
Preferably, there is provided a further step of using a token moving subsystem to move said at least one physical abject over said graphic display device.
Preferably, said token moving subsystem includes an actuable, or robot, arm.
Preferably, the actuable arm comprises an identifier.
Preferably, there is provided a registration step, carried out before said determining step, of indicating a plurality of known positions on said graphic display device, detecting said known positions and mapping between said known positions and said detected positions.
Preferably, said detector comprises a coordinate system of detecting coils arranged on said graphic display device.
Preferably, each of the objects is excitable by a predetermined resonant frequency respectively, wherein said graphic display device is surrounded by an excitation coil operable to output a signal detectable by objects in said set each having a different resonant frequency, to excite said objects.
Preferably, the signal is a wide band signal, which may be implemented as a train of short pulses. Alternatively, it could he a series of frequencies corresponding to resonant frequencies of said identifiers of respective objects in said set.
The embodiments of the present invention may typically be comprised in either one of a group comprising a game and a simulation.
According to a second aspect of the present invention, there is provided a device for detecting physical objects, each object having a detectable identifier, the objects being disposed in association with a graphic display device, comprising
a detector operable to detect a location of said identifier relative to said graphic display device, and to output a signal bearing information of said first location,
wherein said device is operable to determine, by electronic processing, from said signal, a relative location of said physical object in relation to said graphic display device.
Preferably, there is provided a set of physical objects to be detected and said identifier is unique to each physical object within said set. in a preferred embodiment, said detector is a camera and said electronic processing comprises image processing, preferably, said identifier is a visually sensible mark.
Preferably, said visually sensible mark is selected for effectiveness in conjunction with an image processing algorithm being used.
In an alternative embodiment, said identifier is a resonant circuit having a resonant frequency.
Preferably, there is provided a set of physical objects to be detected, each object having a unique resonant frequency.
An embodiment has a grid laid out over said graphic display device, said grid comprising conductors.
Preferably, said conductor, are embedded in at least one transparent foil. A particular embodiment uses two foils.
Preferably, a first set of conductors in said grid serve as transmitter conductors to transmit signals tuned to cause resonance in a correspondingly tuned physical object, and a second set of conductors serve as receivers of resonance signals from a closely located physical object, thereby enabling said device to locate a physical object.
Preferably, said first set of conductors is embedded in a first transparent foil and said second set of conductors is embedded in a second transparent foil.
In a particularly preferred embodiment, there is provided at least one electro-optic sensor for detecting the position of at least one of said foils on said graphic display device.
A preferred embodiment further has a coil surrounding said graphic display device, said coil being operable to transmit a signal able to cause resonance in a physical object, said grid being operable to pick up said resonance via conductors close to said resonating physical object and thereby to locate said physical object.
Preferably, said signal is able to cause resonance in physical objects having a range of resonant frequencies.
Preferably, the signal is a wide band signal.
Preferably, the signal comprises a train of short pulses.
Preferably, the signal comprises a series of frequencies corresponding to resonant frequencies of said identifiers of respective objects in said set.
Preferably, said electronic processing comprises identifying frequencies appearing on individual conductors of said grid following the issuance of said signal.
Preferably, said electronic processing comprises a fast Fourier transform.
Alternatively, given that the frequencies of said physical objects are known, said electronic processing comprises frequency correlation.
In an embodiment there are provided unique storage positions for each physical object.
In a preferred embodiment there is provided a set of physical objects to be detected, the device comprising device following functionality, operable to infer from knowledge of a previous position of a first physical object, knowledge of at least one rule for moving said physical object, and a detected position of said set of physical objects following a move, the current position of said first physical object.
An embodiment provides at least one sensible die for selecting a score based on its orientation, wherein said detector is operable to determine the orientation of said die, said device thereby being operable to deduce said score.
Preferably, said sensible die comprises a plurality of resonant circuits each one being associated with a different orientation of said die and being activated when said die is in the respective orientation, and wherein said detector is operable to detect said resonant frequency.
Preferably, said sensible die comprises a weighted switch for selecting between said resonant circuits based on said orientation of said die.
An embodiment may be used in association with a game utilizing at least one die. In the embodiment, the device comprises a score deducer for deducing a score shown by said at least one die from a detected move of said objects.
A preferred embodiment comprises an interface module for interfacing with the detector.
In a preferred embodiment, said interface module is part of an operating system.
According to a third aspect of the invention there is provided a sensible die for use with an electronic game platform, said die having a plurality of orientations and a score associated with each orientation, the die comprising a plurality of signal generating circuits each one being associated with one of said orientations of said die and being selectable for signal generation when said die is in the respective orientation.
In a preferred embodiment the die comprises a weighted switch for selecting between said signal generating circuits based on said orientation of said die and thereby associating each one of said signal generating circuits with a respective orientation.
Preferably, said signal generating circuits are resonant circuits.
Preferably, each said resonant circuit is operable to resonate at a different frequency, thereby indicating said orientation of said die.
For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, purely by way of example, to the accompanying drawings, in which:
FIG. 1 is a block diagram showing a generalized system according to a first embodiment of the present invention,
FIGS. 2a to 2c are generalized diagrams showing visual indicators placed on tokens to enable visual detection according to one embodiment of the present invention.
FIG. 2d is a generalized flow chart showing a procedure for detection using the indicators of FIGS. 2a to 2c, 
FIG. 3 is a generalized flow chart showing how detection systems may be incorporated into gameplay,
FIG. 4 is a generalized block diagram illustrating the means of calibrating a camera for visual detection,
FIG. 5 is a generalized diagram showing a game board having playing pieces, usable in accordance with embodiments of the present invention,
FIG. 6 is a block diagram showing elements of a game playing system in accordance with an embodiment of the present invention,
FIGS. 7 and 8 are schematic diagrams showing first and second transparent foils for placing on a game board in accordance with embodiments of the present invention,
FIG. 9 is a schematic diagram showing the superposition of the foils of FIGS. 7 and 8,
FIG. 10 is a schematic diagram illustrating the detection of a single token in accordance with an embodiment of the present invention,
FIG. 11 is a schematic diagram indicating magnetic flux between a token and inductive coils,
FIG. 12 is a generalized diagram showing an electronic game board according to a third embodiment of the present invention,
FIG. 13 is a generalized schematic diagram illustrating the detection of a single token according to the third embodiment of the present invention,
FIG. 14 is a generalized diagram showing internal circuitry of a token for use in accordance with the third embodiment of the present invention,
FIG. 15 is a generalized circuit diagram illustrating circuitry for detecting the position of tokens of a gameboard in accordance with the third embodiment of the present invention,
FIGS. 16a and 16b are generalized waveform timing diagrams showing an excitation signal and a corresponding detection signal in accordance with the third embodiment of the present invention,
FIG. 17 is a generalized block diagram at the system level for a platform for games or simulations,
FIG. 18 is a generalized block diagram showing how the platform of FIG. 17 may interact with other platforms, compatible or otherwise over a network,
FIG. 19 is a generalized schematic diagram showing a playing surface with a storage tray for use with embodiments of the present invention, and
FIG. 20 is a generalized schematic diagram showing the use of the robot arm in moving tokens.
FIG. 21 is a generalized diagram showing a sensible die operable in accordance with embodiments of the present invention.
FIG. 22 is a simplified diagram showing a further preferred embodiment of the present invention in which the location of a token on a playing surface is calculated from differences in the signal received at each of a plurality of receivers.